1998 MARS ORBITER, LANDER, MICROPROBES SET FOR LAUNCH

NASA embarks on a return trip to Mars this winter with two spacecraft
launches that will first send an orbiter to circle the red planet, then
follow with another to land on the frigid, barren steppe near the edge of
Mars' south polar cap. Piggybacking on the lander will be two small probes
that will smash into the Martian surface to test new technologies.

Mars Climate Orbiter, scheduled for launch Dec. 10, and Mars Polar Lander,
scheduled for launch Jan. 3, will seek clues to the history of climate
change on Mars. Both will be launched atop identical Delta II launch
vehicles from Launch Complex 17 A and B at Cape Canaveral Air Station, FL,
carrying instruments to map the planet's surface, profile the structure of
the atmosphere, detect surface ice reservoirs and dig for traces of water
beneath Mars' rusty surface.

The lander also carries a pair of basketball-sized microprobes that will be
released as the lander approaches Mars and dive toward the planet's surface,
penetrating up to about 1 meter (3 feet) underground to test 10 new
technologies, including a science instrument to search for traces of water
ice. The microprobe project, called Deep Space 2, is part of NASA's New
Millennium Program.

The missions are the second installment in NASA's long-term program of
robotic exploration of Mars, which was initiated with the 1996 launches of
the currently orbiting Mars Global Surveyor and the Mars Pathfinder lander
and rover.

The 1998 missions will advance our understanding of Mars' climate history
and the planet's current water resources by digging into the enigmatic
layered terrain near one of its poles for the first time. Instruments
onboard the orbiter and lander will analyze surface materials, frost,
weather patterns and interactions between the surface and atmosphere to
better understand how the climate of Mars has changed over time.

Key scientific objectives are to determine how water and dust move about the
planet and where water, in particular, resides on Mars today. Water once
flowed on Mars, but where did it go? Clues may be found in the geologic
record provided by the polar layered terrain, whose alternating bands of
color seem to contain different mixtures of dust and ice. Like growth rings
of trees, these layered geological bands may help reveal the secret past of
climate change on Mars and help determine whether it was driven by a
catastrophic change, episodic variations or merely a gradual evolution in
the planet's environment.

Today the Martian atmosphere is so thin and cold that it does not rain;
liquid water does not last on the surface, but quickly freezes into ice or
evaporates and resides in the atmosphere. The temporary polar frosts which
advance and retreat with the seasons are made mostly of condensed carbon
dioxide, the major constituent of the Martian atmosphere. But the planet
also hosts both water-ice clouds and dust storms, the latter ranging in
scale from local to global. If typical amounts of atmospheric dust and water
were concentrated today in the polar regions, they might deposit a fine
layer every year, so that the top meter (or yard) of the polar layered
terrains could be a well-preserved record showing 100,000 years of Martian
geology and climatology.

Nine and a half months after launch, in September 1999, Mars Climate Orbiter
will fire its main engine to put itself into an elliptical orbit around
Mars. The spacecraft will then skim through Mars' upper atmosphere for
several weeks in a technique called aerobraking to reduce velocity and
circularize its orbit. Friction against the spacecraft's single,
5.5-meter-long (18-foot) solar array will slow the spacecraft as it dips
into the atmosphere each orbit, reducing its orbit period from more than 14
hours to 2 hours.

Finally, the spacecraft will use its thrusters to settle into a polar,
nearly circular orbit averaging 421 kilometers (262 miles) above the
surface. From there, the orbiter will await the arrival of Mars Polar Lander
and serve as a radio relay satellite during the lander's surface mission.
After the lander's mission is over, the orbiter will begin routine
monitoring of the atmosphere, surface and polar caps for a complete Martian
year (687 Earth days), the equivalent of almost two Earth years.

The orbiter carries two science instruments: the Pressure Modulator Infrared
Radiometer, a copy of the atmospheric sounder on the Mars Observer
spacecraft lost in 1993, and the Mars Color Imager, a new, light-weight
imager combining wide-and medium-angle cameras. The radiometer will measure
temperatures, dust, water vapor and clouds by using a mirror to scan the
atmosphere from the Martian surface up to 80 kilometers (50 miles) above the
planet's limb.

Meanwhile, the imager will gather horizon-to-horizon images at up to
kilometer-scale (half-mile-scale) resolutions, which will then be combined
to produce daily global weather images. The camera will also image surface
features and produce a map with 40-meter (130-foot) resolution in several
colors, to provide unprecedented views of Mars' surface.

Mars Polar Lander, launched a month after the orbiter is on its way, will
arrive in December 1999, two to three weeks after the orbiter has finished
aerobraking. The lander is aimed toward a target sector within the edge of
the layered terrain near Mars' south pole. The exact landing site
coordinates will be adjusted as late as August 1999, based on images and
altimeter data from the currently orbiting Mars Global Surveyor.

Like Mars Pathfinder, Mars Polar Lander will dive directly into the Martian
atmosphere, using an aeroshell and parachute scaled down from Pathfinder's
design to slow its initial descent. The smaller Mars Polar Lander will not
use airbags, but instead will rely on onboard guidance and retro-rockets to
land softly on the layered terrain near the south polar cap a few weeks
after the seasonal carbon dioxide frosts have disappeared. After the heat
shield is jettisoned, a camera will take a series of pictures of the landing
site as the spacecraft descends.

As it approaches Mars about 10 minutes before touchdown, the lander will
release the two Deep Space 2 microprobes. Once released, the projectiles
will collect atmospheric data before they crash at about 200 meters per
second (400 miles per hour) and bury themselves beneath the Martian surface.
The microprobes will test the ability of very small spacecraft to deploy
future instruments for soil sampling, meteorology and seismic monitoring. A
key instrument will draw a tiny soil sample into a chamber, heat it and use
a miniature laser to look for signs of vaporized water ice.

About 100 kilometers (60 miles) away from the microprobe impact sites, Mars
Polar Lander will dig into the top of the terrain using a 2-meter-long
(6-1/2-foot) robotic arm. A camera mounted on the robotic arm will image the
walls of the trench, viewing the texture of the surface material and looking
for fine-scale layering. The robotic arm will also deliver soil samples to a
thermal and evolved gas analyzer, an instrument that will heat the samples
to detect water and carbon dioxide. An onboard weather station will take
daily readings of wind temperature and pressure, and seek traces of water
vapor. A stereo imager perched atop a 1.5-meter (5-foot) mast will
photograph the landscape surrounding the spacecraft. All of these
instruments are part of an integrated science payload called the Mars
Volatiles and Climate Surveyor.

Also onboard the lander is a light detection and ranging (lidar) experiment
provided by Russia's Space Research Institute. The instrument will detect
and determine the altitude of atmospheric dust hazes and ice clouds above
the lander. Inside the instrument is a small microphone, furnished by the
Planetary Society, Pasadena, CA, which will record the sounds of wind gusts,
blowing dust and mechanical operations onboard the spacecraft itself.

The lander is expected to operate on the surface for 60 to 90 Martian days
through the planet's southern summer (a Martian day is 24 hours, 37
minutes). The mission will continue until the spacecraft can no longer
protect itself from the cold and dark of lengthening nights and the return
of the Martian seasonal polar frosts.

The Mars Climate Orbiter, Mars Polar Lander and Deep Space 2 missions are
managed by the Jet Propulsion Laboratory for NASA's Office of Space Science,
Washington, DC. Lockheed Martin Astronautics Inc., Denver, CO, is the
agency's industrial partner for development and operation of the orbiter and
lander spacecraft. JPL designed and built the Deep Space 2 microprobes. JPL
is a division of the California Institute of Technology, Pasadena, CA.

SCIENCE TEAM CHOSEN FOR TECHNOLOGY VALIDATION MISSION TO EXPLORE THE SUBSURFACE OF MARS

Nine researchers have been selected to be the Science Team
for the Mars Microprobes, a technology validation mission that
will hitchhike to the red planet aboard NASA's 1998 Mars Polar
Lander mission.

Two identical probes will be carried as a secondary payload
on the lander, due for launch in January 1999. Following an 11-
month cruise, the Microprobes will separate from the lander before
it enters the Martian atmosphere, and then hit the ground at
approximately 400 mph.

During the impact, each microprobe will separate into two
sections: the forebody and its instruments will penetrate up to
six feet (two meters) below the surface, while the aftbody will
remain near the surface to communicate with a radio relay on
NASA's Mars Global Surveyor orbiter while making meteorological
measurements.

The nine selected scientists are:

David Catling, NASA Ames Research Center, Moffett Field, CA

Ralph Lorenz, University of Arizona, Tucson

Julio Magalhaes, NASA Ames Research Center

Jeffrey Moersch, NASA Ames Research Center

Paul Morgan, Northern Arizona Univ., Flagstaff

James Murphy, NASA Ames Research Center

Bruce Murray, California Institute of Technology, Pasadena

Marsha Presley, Arizona State Univ., Phoenix

Aaron Zent, NASA Ames Research Center

The scientific objectives of the Mars Microprobes include
searching for the presence of water ice in the soil and
characterizing its thermal and physical properties. A small drill
will bring a soil sample inside the probe, heat it, and look for
the presence of water vapor using a tunable diode laser. An
impact accelerometer will measure the rate at which the probes
come to rest, giving an indication of the hardness of the soil and
any layers present. Temperature sensors will estimate how well
the Martian soil conducts heat, a property sensitive to different
soil properties such as grain size and water content. A sensor at
the surface will measure atmospheric pressure in tandem with a
sensor on the Mars Polar Lander.

The Mars Microprobes mission, also known as Deep Space-2 (DS-
2), is scheduled to be the second launch in NASA's New Millennium
Program of technology validation flights, designed to enable
advanced science missions in the 21st century.

"I'm delighted with the selection of this excellent group of
investigators. The Mars Microprobe will give us a glimpse of the
subsurface of Mars, which in many ways is a window into the
planet's history," said Dr. Suzanne Smrekar, the DS-2 project
scientist at NASA's Jet Propulsion Laboratory, Pasadena, CA. "The
region of Mars we will explore is similar to Earth's polar regions
in that it is believed to collect ice and dust over many millions
of years. By studying the history of Mars and its climate, we are
likely to better understand the more complex system on our own
planet."

In addition to the miniaturized science instruments capable
of surviving high velocity impact, technologies to be tested on
DS-2 include a non-erosive, lightweight, single-stage atmospheric
entry system or aeroshell; power microelectronics with mixed
digital/analog advanced integrated circuits; an ultra-low
temperature lithium battery; an advanced three-dimensional
microcontroller; and flexible interconnects for system cabling.

"The combination of a single-stage entry vehicle with
electronics and instrumentation that can survive very high impact
loads will enable us to design a whole new class of very small,
rugged spacecraft for the in-situ exploration of the planets,"
explained Sarah Gavit, DS-2 project manager at JPL.

"Slamming high-precision science instruments into the surface
of Mars at 400 mph is very challenging, no doubt about it! But
once this type of technology is demonstrated, we can envision
future missions that could sample numerous regions on Mars or make
network measurements of global weather and possible Marsquakes,"
said DS-2 program scientist Dr. Michael Meyer of NASA
Headquarters, Washington, DC.

LORENZ NAMED TO MARS MICROPROBE PROJECT SCIENCE TEAM

A planetary scientist from The University of Arizona in Tucson has been
named to the science team for an experiment piggybacking on the 1998 Mars
Surveyor Lander, a mission that carries UA instruments in the main payload
package.

NASA today named Ralph D. Lorenz, 28, a research associate in the UA
Lunar and Planetary Laboratory, to the science team of the $2.8 million Mars
Microprobe Project that will ride on the 98 lander mission, scheduled for
launch in January 1999. Lorenz, who models planetary climates, also works
on a UA-built experiment called TEGA, part of the Mars Volatiles and Climate
Surveyor (MVACS), the integrated payload package on the lander.

The microprobes are two basketball-size aeroshells that will ride
underneath the lander s solar panels during the spacecraft s 11 month journey
to Mars. They will crash onto the Martian surface at a velocity of about 200
meters per second. Each aeroshell will shatter on impact, releasing a
miniature two-piece science probe that will punch into the soil at a
depth of up to 2 meters. The microprobes are primarily to test key
technologies for future missions that will land multiple microprobes on the
surfaces of other worlds, but they also have a major science goal, which is to
determine if water ice is present in the Martian subsurface. The tiny science
stations will also measure temperature and monitor local Martian
weather for 50 hours in the very cold Mars environment.

Whether batteries on the microprobes survive impact is uncertain, Lorenz
noted. So far, no penetrator has successfully reached another planet or
moon. The penetrators will strike the surface with a force equivalent to
80,000 times their weight here on Earth, he added.

The 98 Mars Surveyor Lander is to discover what turned Mars from a
warm, wet place to the cold, arid planet we see today. It is targeted to land on
the strange layered terrain at the edge of the south polar ice cap. Here,
Lorenz wrote in the Sept. 20, 1997, issue of New Scientist, a
record of the Martian climate may be written in the geology of the area in the
same way that the climate record on Earth is reflected in ocean sediments,
ice cores and tree rings. Lorenz plans to look for layers beneath the surface
by analyzing the impact force recorded by an accelerometer on each
microprobe.

The three main theories of what happened to transform Mars climate read
like the plot of a detective novel, Lorenz wrote. Mars volatiles may have
been murdered by slow, drawn-out death by suffocation as impacts from
asteroids and comets eroded the atmosphere. Or perhaps it was death by
suicide, a case where Martian silicate rocks reacted with atmospheric
carbon dioxide to form carbonate minerals: The atmosphere would gradually
have been sucked into the surface of the planet. Or maybe the Red Planet
died of natural causes that resulted when, gripped in a severe ice age, the
planet s carbon dioxide atmosphere condensed to form permafrost at the
poles or beneath the entire surface. The permafrost would be hidden from
orbiting spacecraft by the dust that covers Mars.

The main solar-powered payload, MVACS, should collect data for up to
seven months during the Martian summer of 1999. During that time it should
provide vital clues to the planet s cause of death, Lorenz said. When the
winter sun sinks low on the Mars horizon, MVAC s solar panels will no longer
power the lander. But scientists hope that MVACS may come back to life the
following spring, almost 400 days later, he added.

UA planetary sciences professor William V. Boynton heads the team that
built the TEGA, or Thermal and Evolved Gas Analyzer, on MVACS. It consists
of eight tiny ceramic ovens, each no wider across than a dime, that will use
electric current to heat soil samples scooped up by the robotic arm. By
measuring the amount of energy required to warm the soil at a certain rate,
scientists will detect how much frozen water and carbon dioxide are in the
soil, as well as the presence of various minerals.

Peter H. Smith, principal investigator on the Imager for Mars Pathfinder
(IMP) and an associate research scientist at the UA Lunar and Planetary
Laboratory, heads the team that built the Surface Stereo Imager, or SSI, for
the 98 Mars Surveyor Lander. It is a copy of the stereoscopic, color-sensitive
IMP. Smith s team also built the Robotic Arm Camera, or RAC, on
MVACS. It is a more near-sighted camera mounted at the end of a two-meter
robotic arm. The arm will collect surface and subsurface samples of Martian
soil. RAC will take close-up pictures of these samples.

MARS PENETRATORS SUCCESSFULLY COMPLETE CRUCIAL SUBSYSTEM TEST

Two miniature science probes designed to penetrate the
Martian surface and analyze the water vapor content of the
planet's subterranean soil in 1999 have successfully completed a
crucial subsystem test deep in the New Mexico desert.

This successful check of the batteries and soil collection
drill of the mission known as Deep Space 2 (DS2) provides a "green
light" for subsequent integrated system tests next spring, said
Sarah Gavit, DS2 project manager at NASA's Jet Propulsion
Laboratory (JPL), Pasadena, CA. The DS2 mission hardware will be
launched in January 1999, mounted on the Mars Surveyor '98 Lander.
Both missions will arrive on Mars in December 1999.

DS2 is the second scheduled launch in NASA's New Millennium
Program, which is designed to test new advanced technologies prior
to their use on science missions in the 21st century. DS2 will
validate the ability of small probes loaded with sensitive,
miniaturized instruments to analyze the terrain of planets and
moons throughout the Solar System.

In the late October test, a 4.4-pound (two-kilogram)
prototype probe containing a soil collection drill and a circular
group of eight lithium thyonal chloride cells -- forming two
batteries -- was shot into the ground at more than 400 mph (644
kilometers per hour). The drill survived a 20,000-G impact, and
the batteries, nestled inside a custom-designed casing, survived a
45,000-G impact intact. Both continued to function as designed.
One G is the normal force of gravity on Earth.

"The Mars Pathfinder lander experienced about 19 G's when it
hit the Martian terrain in July, so you can see that we are
working at enormous rates of deceleration," explained Gavit. "One
of our biggest challenges has been to find a way for our
components to survive such a high deceleration force. The items
at highest risk are the batteries, their packaging and the motor
drill assembly.

"Although the recent test was one in a long series, it was
the first test using flight-like hardware and packaging, so it
served as a complete qualification of the battery and drill
subsystems," she added.

The probe design features two modules: a circular aftbody,
five inches (13 centimeters) in diameter, containing the
batteries, that remains atop the surface; and a four-inch-long
(10-centimeter) forebody, containing the drill and a soil analysis
instrument, that should burrow up to six feet (1.8 meters) into
the Martian soil. The two modules are connected via a flex cable
that unravels as the forebody dives into the soil after a freefall
impact.

Once in the ground, the soil collection drill slowly twists
out from the side of the forebody and retracts a tiny soil sample
into a chamber within the forebody, where it is analyzed by a
water detection instrument. This instrument's key feature is a
miniature tunable diode laser, similar in principle to the lasers
used in consumer CD players. The soil sample is then heated,
creating a vapor that passes through the path of the laser beam if
water is indeed present. This resulting change in the intensity
of the laser light indicates the amount of water, if any, to be
found in the Martian soil sample.

The aftbody features batteries developed just for DS2. These
batteries can operate down to minus 112 degrees F (minus 80
degrees Celsius), making them the only batteries of this type with
the dual capability of being able to survive the strong impact and
work in low temperatures. The aftbody also includes a micro-
telecommunications system that, together with miniaturized
electronics in the forebody, will relay the probe's findings to
the orbiting Mars Global Surveyor spacecraft for transmission to
Earth via NASA's Deep Space Network.

The Oct. 29 test took place at the New Mexico Institute of
Mining Technology's Energetic Materials Research and Test Center
in Socorro, NM. It was the 53rd test of DS2 hardware since the
spring of 1996, beginning with early tests of preliminary battery
and drill designs, among many other components.

JPL manages the New Millennium Program for NASA's Office of
Space Science and Office of Mission to Planet Earth, Washington,
DC. JPL is a division of the California Institute of Technology,
Pasadena, CA.

NASA Headquarters, Washington
Jet Propulsion Laboratory, Pasadena, CA

September 24, 1996

SECOND NEW MILLENNIUM FLIGHT WILL SEND MICROPROBES TO THE SURFACE OF MARS

Two small science probes will be sent to Mars in 1999
to demonstrate innovative new technologies brought to the
forefront by NASA's New Millennium program.

Under terms of a new agreement between the New
Millennium and Mars Exploration programs, the microprobes
will hitchhike to Mars aboard NASA's 1998 Mars Surveyor Lander.

"A successful demonstration of the microprobe
technologies will enable a wide range of scientific
activities that would not be affordable with conventional
technologies," said Dr. John McNamee, manager of the 1998
Mars Surveyor Lander and Orbiter project at NASA's Jet
Propulsion Laboratory (JPL), Pasadena, CA.

"In particular, scientific investigations which
require a relatively large number of surface stations
distributed over the surface of Mars, such as seismic or
meteorology networks, will be made possible by the microprobe
concept," McNamee said. "In addition, microprobe penetrators
may be the most efficient and effective way of obtaining soil
samples and measurements from below the sterilized Martian surface."

In the process of enabling future characterization
of the Martian climate by a meteorological network, the Mars
microprobes will complement the climate-related scientific
focus of the 1998 Mars Surveyor Lander by demonstrating an
advanced, rugged microlaser system for detecting subsurface
water. Such data on polar subsurface water, in the form of
ice, should help put limits on scientific projections for the
global abundance of water on Mars.

Future missions to the planet could use similar
penetrators to search for subsurface ice and minerals that
could contribute to the search for evidence of life on Mars.

The 1998 Mars Surveyor Lander will be launched in
January 1999 and spend 11 months en route to the Red Planet.
Just prior to its entry into the Martian atmosphere, the
microprobes, mounted on the spacecraft's cruise ring, will
separate and plummet to the surface using a single-stage
entry aeroshell system. Chosen for its simplicity, this
aeroshell does not separate from the microprobes, as have
traditional aeroshells on previous spacecraft, such as the
Mars Pathfinder and the Viking landers of the mid-1970s.

The probes will plunge into the surface of Mars at an
extremely high velocity of about 446 miles per hour (200
meters per second) to ensure maximum penetration of the
Martian terrain. They should impact the surface within 120
miles (200 kilometers) of the main Mars '98 lander, which is
targeted for the planet's icy south polar region.

Upon impact, the aeroshells will shatter and the
microprobes will split into a forebody and aftbody system.
The forebody, which will be lodged between one to six feet
underground, will contain the primary electronics and
instruments. The aftbody, connected to the forebody by an
electrical cable, will stay close to the surface to collect
meteorological data and deploy an antenna for relaying data
back to Earth.

The microprobes will weigh less than 4.5 pounds (2
kilograms) each and be designed to withstand both very low
temperatures and high deceleration. Each highly integrated
package will include a command and data system, a
telecommunications system, a power system, and primary and
secondary instruments. Nearly all electrical and mechanical
designs will be new to space flight.

"In addition to a team of industrial partners that
will help develop advanced technologies to be demonstrated
during the mission, we have just selected Lockheed Martin
Electro-Optical Systems as a primary industry partner to
participate in the integration and test program for the
microprobes," said Sarah Gavit, Mars microprobe flight leader
at JPL.

Technologies proposed for demonstration on this
second New Millennium flight include a light weight, single-
stage entry aeroshell, a miniature, programmable
telecommunication subsystem, power microelectronics with
mixed digital/analog integrated circuits, an ultra low-
temperature lithium battery, a microcontroller and flexible
interconnects for system cabling.

In-situ instrument technologies for making direct
measurements of the Martian surface will include a water and
soil sample experiment, a meteorological pressure sensor and
temperature sensors for measuring the thermal properties of
the Martian soil.

"The Mars microprobe mission will help chart the
course for NASA's vision of space science in the 21st
century, a vision that incorporates the concept of 'network
science' through the use of multiple planetary landers," said
Kane Casani, manager of the New Millennium program. The
probes will become the first technology to be validated in
this new network approach to planetary science.

"Networks of spacecraft will address dynamic, complex
systems," Casani said. "For example, a single lander can
report on the weather at one spot on a planet, but a network
of landers is needed to characterize the planet's dynamic
climate. Similarly, a single seismometer will indicate if a
quake has occurred on a planet, but a network of seismometers
can measure the size of a planetary core. We need multiple
spacecraft to go beyond our initial reconnaissance to
completely characterize dynamic planetary systems the way we
are able to do on Earth."

The New Millennium program is managed by JPL for
NASA's Office of Space Science and Office of Mission to
Planet Earth, Washington, DC. The Mars `98 lander, managed
by JPL for the Office of Space Science, is in development at
Lockheed Martin Astronautics Corp., Denver, CO, under
contract to JPL.